Experiences add new meaning to things. That is why a particular song may be felt more impressive and meaningful than many others. However, such special meanings and perceptions can radically change when a person is under the influence of psychedelic drug Lysergic Acid Diethylamide.
Why such a change in attribution of meaning happens has been answered in a new research.
A new research has revealed that there are specific receptors and neurochemicals in the brain that undertake such changes when there is drug in the system.
The findings have been published in Current Biology on Jan. 26.
The research adds a new understanding of human experience and also provide clues in treating psychiatric phobias emanating from aberrations in personal judgments of sensory experiences.
"Our results increase our understanding of how personal relevance attribution is enabled in the brain," said Katrin Preller of the Zürich University Hospital for Psychiatry.
Attribution Of Meaning
Studies showed LSD alters the attribution of meaning by upsetting the personal relevance with respect to the environment. That breeds changes in the self-perception and a blurring of the boundary with the outside world.
So far there was no clarity on the relevant parts of the brain and neurochemicals responsible for such changes.
During the experiment, participants were observed for the effects of LSD on mood, consciousness, and anxiety. Subsequent erosion of those effects when another drug, ketanserin, was then administered. Ketanserin blocks LSD's ability to act on receptors known as 5-HT2ARs.
The influence of LSD on the attribution of meaning to things was judged by a ranking process in the experiment.
Among the songs selected, some were dear to the participants while others were neutral or meaningless.
To their surprise, researchers found musical pieces that were previously dubbed meaningless gained a special meaning when the same individuals ranked them under the influence of LSD.
Opposite results, however, flowed when participants took the second drug that suppressed LSD's effect on the brain's serotonin receptors. The rankings also changed.
Detailed brain imaging showed there were specific brain areas responsible for such changes in attributions.
Treatment For Aberrations
Preller said personal meaning and attribution after the modulation by LSD are processed by the 5-HT2A receptors and cortical midline structures handling the experience of self.
Highlighting the significance of the findings, researchers also noted that stimulation of 5-HT2A receptors can be suitably targeted for treating psychiatric illnesses that follow changes in personal relevance attributions.
How LSD Works?
As a hallucinogen, even a small dose of 100 micrograms of LSD can have strong effects that may last for more than 12 hours.
The drastic intensity of LSD has been traced to its power in binding to a receptor in the brain, which researchers have failed to detect since the 1950s.
"This gives us tremendous insights into how it exerts its profound effects on human consciousness. And it only took 20 years," says Bryan Roth, a psychiatrist, and researcher at the University of North Carolina at Chapel Hill.
The team made a snapshot of LSD sticking to the serotonin 2b receptor and also the serotonin 2a receptor.
As and when LSD fits into the serotonin 2b receptor, a loop of protein slips over the top of the drug and blocks the release of the chemical. The overhang keeps LSD stuck within the receptor longer and explains the long-lasting effects, Roth added.
Under the influence of LSD, people feel that the boundary that separates them from the rest of the world has vanished.
The magnetic resonance images of the brain of people on LSD shows this "ego dissolution."
During ego dissolution, regions in the brain involved in higher cognition become hyper-connected. According to Enzo Tagliazucchi of the Royal Netherlands Academy of Sciences, psychedelic drugs distort reality and breed illusions.